1. Field of the Invention
A work-holding hydraulically actuated clamp which has a projecting forward end. This forward end is formed with two cam surfaces which actuate an inclined jaw slidably carried in and by a dovetail. This piston is reciprocably moved and forwardly moves the jaw forward and down and a reverse motion of the piston causes the jaw to raise and move rearward.
2. Description of the Prior Art
Work-holding clamps are well known in the art and are widely used for holding work that has to be machined in and by metal working equipment. In particular, work-holders having inclined jaws are well known and are shown in U.S. Pat. No. 2,637,249 to H. SWENSON as issued on May 5, 1953. A clamp or vise is also seen in the patent to RZEPELA, U.S. Pat. No. 2,667,799 as issued on Feb. 2, 1954. A more recent machine tool clamp assembly is seen in U.S. Pat. No. 3,595,112 to DeGEORGE as issued on July 27, 1971.
Hydraulic action for clamping is also known but in the present invention the ram is moved by pressurized fluid to and fro or in and out and the forward end is especially contoured to not only provide a forward and downward clamping actuation but the withdrawal motion causes this ram to engage the jaw clamp end to move it up and away from the held work. Fluid actuation is seen in U.S. Pat. No. 3,603,579 as issued to ODOM on Sept. 7, 1971. In the prior art devices shown by domestic and foreign patents a holding clamp with hydraulic actuation for applying holding and withdrawing pressure by a piston is not shown or known to Applicant. In a reduced-to-practice clamp in a small size as shown in the drawings the jaw movement is approximately one-quarter inch with a clamping force of about thirty-five hundred pounds. The hydraulic pressure is anticipated to be about thirty-five hundred p.s.i. This hydraulic clamp, while offering a low profile, provides a positive holding action and a positive unclamping in and to its return action.